The period can be notoriously difficult to operate in with teams unwilling to sell their prized assets and demand high.
There will be a number of high-profile deals clubs in the third tier may want to replicate or avoid at all costs.
Click through the list of some of the best and worst League One transfers in recent history.
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5. 2018-19: Paul Downing - Blackburn to Doncaster (loan)
Downing helped Donny to the top-six and played both legs of their play-off semi-final defeat to Charlton. His stellar performances prompted Pompey to sign him permanently in the summer of 2019. (Photo by Laurence Griffiths/Getty Images) Photo: Laurence Griffiths
6. 2019-20: Gary Madine (Cardiff to Blackpool)
After featuring in the Premier League for Cardiff, Blackpool secured his services in 2019. The decision turned out to be a genius piece of business with the Tangerines gaining promotion via the play-offs 18-months later, while Madine continues to score in the second tier this term. (Photo by Clive Brunskill/Getty Images) Photo: Clive Brunskill
7. 2019-20: Marcus Browne (Middlesbrough to Oxford United) - loan
Browne was an ever-present for Karl Robinson's side and helped them finish in the top-six. The Englishman scored against Pompey in the second leg of their play-off success, but couldn't help them reach the Championship after losing to Wycombe in the final. (Photo by Alex Davidson/Getty Images) Photo: Alex Davidson
8. 2020-21: Jayden Stockley (Preston to Charlton Athletic) - loan
Although Stockley couldn't guide the Addicks into the top-six last term, his move to Charlton on-loan in January 2021 gave the London club the edge to his services permanently last summer. He's scored 14 goals in all competitions this season. (Photo by Pete Norton/Getty Images) Photo: Pete Norton